Liquid crystalline model compounds thermal properties

Table 19.2 Thermal properties of liquid crystalline model compounds derived from BB and TA [25]...

The reason for the lower liquid crystalline (LC) temperature of the BB model compound seems to be that the biphenyl unit of this compound was adopting a twisted structure in the LC state [26], Therefore, we prepared various polyarylates containing the BB unit and determined their thermal properties and the moduli of the as-spun fibers, as shown in Table 19.3. 

Other interesting compounds are copper and nickel complexes of (p-alkoxyphenyl)-ma-londialdehydes, 27. The synthesis, characterization, thermal behavior. X-ray diffraction studies and magnetic properties of a number of these complexes were performed by Haase et al. [68]. It was found that nickel complexes show liquid crystalline SmA phases over a broad temperature range with low melting points (85 °C), while copper complexes show nonidentified mesomorphic behavior. This behavior is different from that observed for n = 5 copper complex reported by Blake et al. [69] who observed a nematic phase. Models for the molecular... 

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